1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a power circuit part, a power control method thereof and a display apparatus having the same, and more particularly, to a power circuit part, a power control method thereof and a display apparatus having the same which controls an output direct current (DC) voltage supplied as operating power to elements such as a display to be gradually output, at different levels depending on a voltage level of input alternating current (AC) power.
2. Description of the Related Art
A condenser-input power circuit apparatus which uses a switching mode power supply (SMPS), which may be implemented in a display apparatus including a television (TV), may include a power factor corrector to correct an unavoidable power factor and harmonic distortion when a current waveform becomes a pulse rather than a sine wave. Such power factor corrector typically uses a voltage control loop to convert a DC voltage input through a rectifier into an output DC voltage at a predetermined level to thereby correct the power factor and supply operating power at a necessary level to elements such as a display.
As shown in FIG. 1, a related art power circuit apparatus may receive AC power at various levels starting around approximately 65V or more as commercial input power may depend on countries, territories, or power supply conditions. The power circuit apparatus may then convert such input power into a high DC voltage of approximately 395V at a single level regardless of the size of the input power, and supplies the converted DC voltage as operating power. As a result, AC-DC conversion efficiency of the power circuit apparatus is reduced when the input AC voltage is a low voltage close to approximately 65V. This is because the power circuit apparatus converts the input AC voltage into the single high DC voltage of approximately 395V regardless of whether the AC voltage is a low voltage such as approximately 110 to 120V that is closer to approximately 65V, or a high voltage such as approximately 220 to 240V that is closer to approximately 395V. Accordingly, the parts such as an inductor, field effect transistor (FET) and diode used in a power factor corrector of a power circuit apparatus will need high specifications to operate with a high current and at a high voltage of approximately 395V. Thus, not only does the DC bias increase but the power supply apparatus may become larger and manufacturing costs may increase.
The related art power factor corrector may be controlled to operate even in the case where a high AC voltage of approximately 260V is input as AC power. This may then lead to the voltage stress, which is imposed upon the parts such as a snubber, the FET, and diode of the power factor corrector, to increase. To mitigate the voltage stress, parts with high specifications are implemented thereby increasing the manufacturing costs.
Thus, the power factor corrector only outputs a high DC voltage at a single level of approximately 395V as an output voltage, and this restricts input power setup of a power switching unit such as a DC-DC local link converter (LLC) which controls a voltage and supplies currents at a consistent level to elements.